SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47d83e9ae3e745da74c49ea39f10b62aa8e904071b3d723e6e2925629f22bec2' 
  AND token = 'BqjHnGs1HOKK+w0lDoXJ3hNakhkttrC2vDnQlPcBvXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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