SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1350e0ed7e026c32ae791ba836a538b7b333be43bb01addc571670a62069ef8' 
  AND token = 'PDCmEe1cWAyzJIwkls2dDGYBJXPhfbu8Il8ioQfOlMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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