SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99a4e91b2d31ea567e8fa952b2d802301bc84d2be4cf47067ea80e6cfc68915f' 
  AND token = 'HVlYwEU8cQs1+04pIuwV5yZFAh/5whdXl+Nnw77OlAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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