SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '295566df32e15680c4fab2a67840ab155448723414b13d8cb28a9b126500dfd0' 
  AND token = 'X50E6qahW3soPwVdfpCWKz6EPh8+CSg8bOBaSzx6pZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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