SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfb5deb293c4451da4a2728f0a9f3f4d2b10a2f2595c1888076973b1af89d5ef' 
  AND token = 'ZXr+CIVO1aPlou39jmCzZ4oZjGPvc8mF15khV6vvHwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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