SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '900c3b543d7df30305a1c9500df25d2fdf3a696609365ecb57a717a46c858c4a' 
  AND token = 'MLIpAc+6YYbLwsMrMpH6saM2uGfOyVEaG5jnyXnXJDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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