SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5446bbeddf5aaf890bbc25da578f8454aa4052452c0230b1234c2223e4569df0' 
  AND token = '3touvGqmQk2nEjU5umt7cdikSxt0OuBbS+CGfY8TsU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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