SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3f25c74ec74f7797f7357e0031c901ff4505f2953e92915dc4f78ef123384242' 
  AND token = 'Cn8jbpNacQn7+6IskFPx+ktLa90aD7cK4Zy9iL62GaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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