SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdf0183448a6c321bec403e544e91cea4a1ba824e46d34c07757f37983d2012c' 
  AND token = 'HjK/p0PlZVqwSqL36OPBUXLE2ZBKZRwlgF+gyMvLa3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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