SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bef156b167d6684c0b10036ffb04dd7b58d85c605afcc31a3dd50babffa205e' 
  AND token = 'Fk3fbVcJb4LSoMSLQpfUKEzn+wBahbXKJQY09jLagWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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