SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2c453113382b98d05c0899f91461bc1ec839ed8d718c6d027aed62daacab0f1' 
  AND token = 'Tzq9f3iAc0RMPgdovpcpS1CBZJVnUtnXwoqHqJV22UU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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