SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb66d9557c0f2f52902f5edffba781aec55a65d0fef040b0bc0932c5ffe517dc' 
  AND token = 'Av09peS9RXh/SiChjAEErWGAyuvbMdXoaBoYhEMx/4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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