SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8d7867bdd2349822df7d2ecc55b825f667869d8799e8e326aec25942e72a1a8' 
  AND token = 'RwOh/CQpJeBcEfN7mZ/Tx8l7indReq6yTEJKqBSbOBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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