SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64cacae7f684110dd0126087fd4add691c8e2d052c8146e3a13d3c8b316de8d4' 
  AND token = '1JK6PXkCNxOBnnb44ZH8U2OG0Zvxl5T7m6ogOsdR3+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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