SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5f1ca8c03b4940a44b15c1d55b6ca6677ea4c039818fbc92919d0e6fb9f77b3' 
  AND token = 'jB25zZzYNiuvwtQbUNCb1Lwmm1PZvD2DkFHTJWE641I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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