SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ccc49dc540e199903d664187396345cf21fb9cd34052408aae2fcb61791e60ee' 
  AND token = 'TPUP0ZOvRujT1V9gq7tf9bJjvgyMbXjjuycGVNRiwKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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