SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4946692cdbea5ca364e6408bd747c433c89407ed26583dc3bf9efbf8c11cc94e' 
  AND token = 'BE2bQReR2S0HnyfI3aupjhlAcs2/ZNtvy+Z1SBw7KwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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