SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32e67fa388a4811e9a052675df8b07cbcc96c815a534651f6fd1181bd7529134' 
  AND token = '6lCTDk0pUKTy8jOr5Pjt6wUai5OAI2szNfxHUtO5nvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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