SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83ff27075a544fe5b239fd30a05af10f6826a1e33cc30350382798eb8dbb018f' 
  AND token = 'Mvi12Y79Tf6glSzAh6Ilts0WKsHysPQQDs7Y2ag25Io=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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