SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fe55f927c1f796a5c19a2f9cb0768d7c718e31f772342d74ba3382169b7f5f9' 
  AND token = 'OfEc3/1frjdX1va/Mj8thCyOBli0V/ibavipouRlNQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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