SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e93aca6dc50032a74c54fb9a6b6e1d81bb1034e963b727c00480735131d5807' 
  AND token = 'rDzY0nPMDIxy8FjJnU0hRH81Ol0oh1MbQCCTKQgAyac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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