SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a4c318458e6914de80ffd07443432671c502ef7fbc75820d3191dbc82d76216' 
  AND token = '2Ekn8yMhiaQnaPphxR5CY5Cxm0ctY0Q5kPhRO9r+U+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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