SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d7c194d18231a1ef7de4c66c3b42f31c6a55992a802f401399d06618a6c34fd' 
  AND token = 'LfmJMFAvAnXY5CdagYBqpIGnO1/Q89LZjwSB9uURquQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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