SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67a86fe0582fdf7611e984d08f6ed09cde71603563747903bae0ec9a645cf0f0' 
  AND token = 'RyPu/6fVmXLnKyNizz1nw8FHx2EwDtCNR7JBW1lGgP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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