SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '884b3e6775f31e56682cd7675e9bca73559d5fc0734bef39a0765e042537590c' 
  AND token = 'j1VkclSW2hrkWdm6MDPZ4QWHHRiAZfoe4YmReVp+oqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}