SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c9fea0d60852fc0bd2316fd797a73e40cce29e4755fa865df88976aec72d221a' 
  AND token = 'rcDaXngR7L7drpWNmHwGZKN7QaofLF6JKkkG7EJO+P4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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