SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14d7d14d8c9592e585ce06d84a58db452b87f85352241ef4aaec740c7c6e1c37' 
  AND token = '1BoNX58hl+ZcNjGrT269vYC0Fzo6S4gtf5Hc0SA2KsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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