SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ec24f0656f5023f93121bc091d216a8fd265911cb6b45adf47d552f0be580a9d' 
  AND token = 'zmJFEzCgo+z3dQaqVVt5xrYWQCYgW21vBGILvHTGazg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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