SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a317986ebcf45b437d6440f3ec4848ad13884a55faaf47433a1a02dc979e23ec' 
  AND token = 'Q0vzJv7cHobB08qhIQDHPYPJfQnFEuQkLElC1A+naA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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