SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3459d4b2309c01c1689eca843685fed95ddd22c7efbc9f1d372dacdc4044917c' 
  AND token = 'IlzYedrOQi4ja/BdJeMRilz3XRxaOv9OQLDvXzPMYs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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