SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2e101ffb1e844c0c680565c579b117219fb14b31d8f011987abeab567163632' 
  AND token = 'NuG+x6iIVkycpqSL9sPfqwm/jAWZQhY44SOl7es6Vf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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