SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98465968a82cd4d7ae307a7d634108298ab6616b14eb8a7c6d095a40e1b76d94' 
  AND token = '+asQLCppcSlQUViC/ABv4WKwgODwqhw0yRH5tY96UVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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