SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80121eb4c9e79d52f94b6826525be86d55393db16b1a959604e8b9b8889d8f29' 
  AND token = 'CbpjieO/awfDRuxZERw47g5/UcqANABvgGm7RB2hWLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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