SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e33669f6308797dc7e630451014573fee2187193aeb272ccc78faa9a54b1f03' 
  AND token = 'aAmSCrTc4H6wCUAXXI+mhaNhGrlVQ4YAyjIgbnJigkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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