SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db29eb521f5bd0fd007a0c144444e7d3d437e59236f796e4bd0f900f6c285f57' 
  AND token = '0EizY6/08OKiNBlAJGV8ZRDVdurf+QPVrU2CnPJmtjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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