SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '486e27ee75fdd73eaab73bb57ec62a6b955163ba2316815682de10d28852ae5c' 
  AND token = 'gyaSpTTDYAzRC+9vnE+8qLSsOJKugLZx2gCifidyGvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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