SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0da2d4fab0953fe14cd5fb2bf8f70b4461926576a88fd0657b13372178d7c2c6' 
  AND token = 'j/1x1y5bLBO6ehDw+Mc6l8zo0BlHYyyguYDLhKTjMzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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