SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c24e7f812f9fbcd03c60e83870a78bd6e6b8e28dd105c389482854f074bc4b9' 
  AND token = 'Sfq9LwmzZwo+U3/jKxRDJWaQIWdPGlJOL5bA+AUojIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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