SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc71d0d413fb35cfbc4c59fb503128a289e8288862f9c7af2e096bbab936877d' 
  AND token = 't04uKM7v0cMswCUvfEf2Iv5lLtaXtk2CRQsX4XAiisw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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