SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f25b387c893ab413f7d35161c09ee9aea5764ac48ca0fd6e6990723ab8dbdf0' 
  AND token = 'jnSakHIqCEm51rBcMzOnsN9aIj2Z7GTnn6iQjxdQEXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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