SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52307427db78e55d9307e55eb0d191f891bcd1887d255058ac6fbffbd35c2238' 
  AND token = 'r+skNbo2pfztEnwtlGvlLG88kyUtyayJOeOfwRnCazo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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