SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf32a4043cec42b178652ce751714f59c9aa88f8e65377523d37b7e1c1dc718d' 
  AND token = 'EeMTMXjXh+AYd5oKDdkQFMVxxvySDJ5TOQ8+pNk7uyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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