SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7db959f61aee98c3b7623346836705170a7c8128c75f8fd93222bfac038b6205' 
  AND token = '3whXwDFJAuPSS3x84RXKRfGlqL+CbUep8AIPN6ELWok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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