SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2083159bcb791df98f41578387f00cca7fc98b50334f159d45d65ea28d7e6e8' 
  AND token = 'B+9vGB1CCGv/3Ec5w5XZYqTnJPw6Fr+DzxogH3FAeJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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