SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f073ed0f1f94bee99f90de78ea09f02b919ae8d5bf7f2a6df424d6ce6c642591' 
  AND token = 'JWCTbDlFCHXMPLbeIOrVa9XIB4emuLvh3cREmGxqvpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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