SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c131e9da949ce8bb419b60379e589b7f041e39d259dde7050c5928d23124c7b' 
  AND token = 'ruLJYV5Rp35n6JBdzLzFOT7QZtEdRe61n5bX7v+ADl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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