SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74b16558e12a40e2a0a6653bf5779dd9bff3973290f40be9e282be8520579a70' 
  AND token = 'Gn5tcN439rlXyTsLDNbj4WtOjHBXY7QG0agZWz2j8sI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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