SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7f31fe000195d52231c905dcf815de41c28373de4459317227fd248d6ea66f0' 
  AND token = 'I/vDRwBbNleTnypvoq8UPEb6xuNLVD6RAoJsY0rrP2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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