SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77f69c0b3896daf6921202a9650705a37dac62986e8a93c9bc01e8d942297077' 
  AND token = 'Bny6AIjJTDLyWUENPaxyngDcaOb0yj5zV0mIHyBoiHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}