SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97d83241afe7556ef48063035c3504a752d8e0b6a4202c6f3e21e65aec5ad3ac' 
  AND token = 'jgkhguP/zshXhxfCgvZmWsQnKV9HNAxEmVXprvn/cQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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