SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb5ee821722fe321a8172a327f4c63962401b22f8cfc4bd69cae80c72925d8db' 
  AND token = 'ewWmguQZ3Ovqq8cIJRSahb3bFZWzjhI3YUE2Poc/lJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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