SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb1232973bdf436f7b49ddd30081c596be06b3cf24d71af2e850efe9e54b4d64' 
  AND token = 'FpFaHYdVZgOzzMesIhVEp2uvsXGnyaMeXDWQ3mp21x8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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