SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64c514bc64c9123ae4683feb1086333cb886562dc6a8582cf3ee5a4348f25487' 
  AND token = 'qGjwK07CEq68y4kBQMi6DECo4cqjJqMTtEn2G8aUM0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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