SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9aa67da65c2353c0ab2e69a56c7fcf8a46b12ac766140156c720a63088bab9c' 
  AND token = 'HUKqmQRPncVjKKRkZpurin4zhlFICdfle0kFGGnZcxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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