SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be44eebfd40998f8e962dcf959e1c1adecfa1d37453bf27f5f3eea7f7ba3aa56' 
  AND token = 'hMRvooPl5OAWhX4VKhjwAolEk6uQeZrBFbxUoSrMRz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}