SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4194f567a9697a995b182317927aec0c9bae9f8c4c1e4fc42add4034099e75c' 
  AND token = 'dzLEOqXNVXwCT4zfABo0HTbJEkijYkMCeJ94DGaHy6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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