SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ccac0f6410ee78a63468a2653450a4e6eca700b8fd497cade86a6348a66baf6' 
  AND token = 'ptewpjTRwlq/hklzHCBDWKVh4mHNTCAm2bB2a5cwFzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}