SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d9f13a1d632f4bc8b97f2516a5a744d8d42ead637feaa192015f952c5c54f59' 
  AND token = 'CjFbLQgszxrSHEmdAEBoLsqPb4sIXqY842GqTmawWp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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