SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c52fc2586e181dacd0a6a5db514506e780ed194daa560220f3577bfd01f759a' 
  AND token = 'sSwhIYLx8MnEXUSZGbX+R38YJGKabisQPMqTo5Cz4EI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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