SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a6b30ca7926107f67528779f6640bc9d9acc6e4e040fb5f0144271076753492' 
  AND token = 'jZPnsNlzajw1l1K7OtQlfzYiUaCsSyaG2E3GJgGEAXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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