SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c099ce35d36be748cca856ba9213b0769a53582479f8c9175700134635430e39' 
  AND token = 'ZIjKe3zkA1vUpB4nIbRU5cuUSceNnEIwSBvsklRXAZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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