SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a7f1dbc6c48ba51e9b09e4381cdac3cd8ff2e88e5c8cba4c925aa3138d9d1b7' 
  AND token = 'qzy1gSfX3zbFPDTuosJF3v9fMwIlOQkj3YA8pz1HtLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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