SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2e357197adf89461f9617cb39db6bf2649843e12591f7879acb9f46571f40d8' 
  AND token = 'VA0c05ltQOxTlv06brPM75dF77j+9D2Hnq6q0IObbt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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