SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19919ae9cc36b70c864edce5d8b28831cfde2a9ec8ff98642859add5b690f6df' 
  AND token = 'QU7NMyPx9GmlDg04RLgcfq+zqWFNvo9PY8q9WAVgOP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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