SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abf7157ccd799b85055771c62fe01f1bb85066c01ecaad706e0959cc530d1eb2' 
  AND token = 'QBnCprNGnVoeiN4pN+gQhaHWlUPR6Wx8QlwE4/GMZKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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