SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0acb1f31d992ed15d4cfb0f38de8bc126a8472249001e199ff005ae26005d17' 
  AND token = 'hwoYuArjXXuRF7VjzhhCmGAIrotrhHsicqSYnaLmvSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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