SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f09f3f4a6e9b46bf9c795d29dda10179251047cabb55afd29f4f09062781e40d' 
  AND token = 'sOEhHbdQ8QUlhWsGzNtkvwEflRv490gTV3HLuxSMPLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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