SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '84d036e2ef8355bcf9691fe335fe01b2efc9a20957d61f0be5de4c0dd74a82de' 
  AND token = '1qHrsl5JjPEGQNrvZatG+2jiCHcdNKA3F8mVhoIZ6zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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