SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae58936175b148dbdc36404a2cb4c710ee529ac3f3cc9faece5fd05923457ee4' 
  AND token = 'n07lG9dzQkIIaLe9PMyISUQfP1HBTpuFHbmdyZhVrA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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