SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c3c3fc218710c48a286631af2ebad976a026da8dfa5fe53c734623bf2afc2a4a' 
  AND token = 'TtMgk2v3YyqHf3UrIpOO84aEhPDWhSUgBXcsSK2PDYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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