SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '890eee250048ee2de446af95e9b587a2bac10d275986c8e3bc41477933602881' 
  AND token = 'zyzxjULUGoxCnfyX0d2cH5Fn9Y6C7rG0xNuSe72hJTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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