SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9645596dae2db62660e10dbc950499ea743634f0cfb61d0b3bfbfecd2c8137cd' 
  AND token = 'wVGrQBD3lj7qCa4F3MhTaW+m13kN5L6RRraJJwlOSyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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