SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5a635eacb12c925d737a1914db25b9c730828d6b3555377141700d8f4f192c1' 
  AND token = 'qFkKfbdXXJAWwinTwnjILH0KXQv/sGlgdV1Xmv2oM+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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