SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebe2b596f8dd42d1a76882f7da2877d4f9d0bdfc4a58574e67052f32c9da2d91' 
  AND token = 'GPJyOBD4xjqN+N2pAgloqJqFUWt9XlgI3ILyJTRZV+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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